In small-sized cameras, particularly compact-type cameras that use 35 mm roll film (J135), those which, in addition to its automated exposure and focusing, is capable of automatically operating also the wind and rewind of film by a built-in motor have already been on the market, but in recent years, to such compact-type cameras, there also has been made a proposal of a camera equipped with a taking lens whose focal length is changeable in two steps, the so-called "double-focus lens.
In the double-focus lens, the change of the focal length, in order to keep the focal point on the surface of film simultaneously with the attaching/detaching of a conversion lens, requires an operation of moving the taking lens in its optical axis direction.
In a camera having a lens movable in its optical axis direction, such as a variable-focus camera or a collapsible mount-type camera designed so as to have its lens collapse when not in use and protrude when photographing, if an attempt is made to have this operation made by a motor, a lensmoving mechanism is required in addition to the conventional mechanism, thus causing the camera to be of a large size, bulky to carry about for photographing.
As for the drive mechanism capable of arbitrarily changing the lens-moving operation as well as of winding/rewinding film by a same single motor, there have been several proposals, but they sophisticate the mechanism to complicate handling and also make it difficult to obtain means to automatically initiate the rewind of film upon completion of the use of film, and thus it is the status quo that there are still no complete ones as the drive mechanism for full automatic cameras.